Add option to set cluster TLS cipher suites. (#3228)

* Add option to set cluster TLS cipher suites.

Fixes #3227

command/server/config.go

@@ -42,7 +42,9 @@ type Config struct {
 	DefaultLeaseTTL    time.Duration `hcl:"-"`
 	DefaultLeaseTTLRaw interface{}   `hcl:"default_lease_ttl"`
 
-	ClusterName     string `hcl:"cluster_name"`
+	ClusterName         string `hcl:"cluster_name"`
+	ClusterCipherSuites string `hcl:"cluster_cipher_suites"`
+
 	PluginDirectory string `hcl:"plugin_directory"`
 }
 
@@ -276,6 +278,11 @@ func (c *Config) Merge(c2 *Config) *Config {
 		result.ClusterName = c2.ClusterName
 	}
 
+	result.ClusterCipherSuites = c.ClusterCipherSuites
+	if c2.ClusterCipherSuites != "" {
+		result.ClusterCipherSuites = c2.ClusterCipherSuites
+	}
+
 	result.EnableUI = c.EnableUI
 	if c2.EnableUI {
 		result.EnableUI = c2.EnableUI
@@ -376,6 +383,7 @@ func ParseConfig(d string, logger log.Logger) (*Config, error) {
 		"default_lease_ttl",
 		"max_lease_ttl",
 		"cluster_name",
+		"cluster_cipher_suites",
 		"plugin_directory",
 	}
 	if err := checkHCLKeys(list, valid); err != nil {

command/server/config_test.go

@@ -99,6 +99,8 @@ func TestLoadConfigFile_json(t *testing.T) {
 			DisableClustering: true,
 		},
 
+		ClusterCipherSuites: "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA",
+
 		Telemetry: &Telemetry{
 			StatsiteAddr:                       "baz",
 			StatsdAddr:                         "",

command/server/test-fixtures/config.hcl.json

@@ -4,6 +4,7 @@
 			"address": "127.0.0.1:443"
 		}
 	}],
+	"cluster_cipher_suites": "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA",
 	"storage": {
 		"consul": {
 			"foo": "bar",

helper/tlsutil/tlsutil.go

@@ -23,6 +23,7 @@ func ParseCiphers(cipherStr string) ([]uint16, error) {
 		"TLS_RSA_WITH_3DES_EDE_CBC_SHA":           tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA,
 		"TLS_RSA_WITH_AES_128_CBC_SHA":            tls.TLS_RSA_WITH_AES_128_CBC_SHA,
 		"TLS_RSA_WITH_AES_256_CBC_SHA":            tls.TLS_RSA_WITH_AES_256_CBC_SHA,
+		"TLS_RSA_WITH_AES_128_CBC_SHA256":         tls.TLS_RSA_WITH_AES_128_CBC_SHA256,
 		"TLS_RSA_WITH_AES_128_GCM_SHA256":         tls.TLS_RSA_WITH_AES_128_GCM_SHA256,
 		"TLS_RSA_WITH_AES_256_GCM_SHA384":         tls.TLS_RSA_WITH_AES_256_GCM_SHA384,
 		"TLS_ECDHE_ECDSA_WITH_RC4_128_SHA":        tls.TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
@@ -32,10 +33,14 @@ func ParseCiphers(cipherStr string) ([]uint16, error) {
 		"TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA":     tls.TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
 		"TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA":      tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
 		"TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA":      tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
+		"TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256": tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,
+		"TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256":   tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
 		"TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256":   tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
 		"TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256": tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
 		"TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384":   tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
 		"TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384": tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
+		"TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305":    tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
+		"TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305":  tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,
 	}
 	for _, cipher := range ciphers {
 		if v, ok := cipherMap[cipher]; ok {

helper/tlsutil/tlsutil_test.go

@@ -7,12 +7,12 @@ import (
 )
 
 func TestParseCiphers(t *testing.T) {
-	testOk := "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_256_GCM_SHA384"
+	testOk := "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305"
 	v, err := ParseCiphers(testOk)
 	if err != nil {
 		t.Fatal(err)
 	}
-	if len(v) != 12 {
+	if len(v) != 17 {
 		t.Fatal("missed ciphers after parse")
 	}
 

vault/cluster.go

@@ -398,7 +398,7 @@ func (c *Core) ClusterTLSConfig() (*tls.Config, error) {
 		//c.logger.Trace("core: performing server config lookup")
 		for _, v := range clientHello.SupportedProtos {
 			switch v {
-			case "h2", "req_fw_sb-act_v1":
+			case "h2", requestForwardingALPN:
 			default:
 				return nil, fmt.Errorf("unknown ALPN proto %s", v)
 			}
@@ -414,6 +414,7 @@ func (c *Core) ClusterTLSConfig() (*tls.Config, error) {
 			RootCAs:              caPool,
 			ClientCAs:            caPool,
 			NextProtos:           clientHello.SupportedProtos,
+			CipherSuites:         c.clusterCipherSuites,
 		}
 
 		switch {
@@ -438,6 +439,7 @@ func (c *Core) ClusterTLSConfig() (*tls.Config, error) {
 		GetClientCertificate: clientLookup,
 		GetConfigForClient:   serverConfigLookup,
 		MinVersion:           tls.VersionTLS12,
+		CipherSuites:         c.clusterCipherSuites,
 	}
 
 	var localCert bytes.Buffer

vault/cluster_test.go

@@ -383,3 +383,37 @@ func testCluster_ForwardRequests(t *testing.T, c *TestClusterCore, rootToken, re
 		}
 	}
 }
+
+func TestCluster_CustomCipherSuites(t *testing.T) {
+	cluster := NewTestCluster(t, &CoreConfig{
+		ClusterCipherSuites: "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA",
+	}, nil)
+	cluster.Start()
+	defer cluster.Cleanup()
+	core := cluster.Cores[0]
+
+	// Wait for core to become active
+	TestWaitActive(t, core.Core)
+
+	tlsConf, err := core.Core.ClusterTLSConfig()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	conn, err := tls.Dial("tcp", fmt.Sprintf("%s:%d", core.Listeners[0].Address.IP.String(), core.Listeners[0].Address.Port+105), tlsConf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	err = conn.Handshake()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if conn.ConnectionState().CipherSuite != tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 {
+		var availCiphers string
+		for _, cipher := range core.clusterCipherSuites {
+			availCiphers += fmt.Sprintf("%x ", cipher)
+		}
+		t.Fatalf("got bad negotiated cipher %x, core-set suites are %s", conn.ConnectionState().CipherSuite, availCiphers)
+	}
+}

vault/core.go

@@ -30,6 +30,7 @@ import (
 	"github.com/hashicorp/vault/helper/logformat"
 	"github.com/hashicorp/vault/helper/mlock"
 	"github.com/hashicorp/vault/helper/reload"
+	"github.com/hashicorp/vault/helper/tlsutil"
 	"github.com/hashicorp/vault/logical"
 	"github.com/hashicorp/vault/physical"
 	"github.com/hashicorp/vault/shamir"
@@ -285,6 +286,8 @@ type Core struct {
 	//
 	// Name
 	clusterName string
+	// Specific cipher suites to use for clustering, if any
+	clusterCipherSuites []uint16
 	// Used to modify cluster parameters
 	clusterParamsLock sync.RWMutex
 	// The private key stored in the barrier used for establishing
@@ -395,6 +398,8 @@ type CoreConfig struct {
 
 	ClusterName string `json:"cluster_name" structs:"cluster_name" mapstructure:"cluster_name"`
 
+	ClusterCipherSuites string `json:"cluster_cipher_suites" structs:"cluster_cipher_suites" mapstructure:"cluster_cipher_suites"`
+
 	EnableUI bool `json:"ui" structs:"ui" mapstructure:"ui"`
 
 	PluginDirectory string `json:"plugin_directory" structs:"plugin_directory" mapstructure:"plugin_directory"`
@@ -459,6 +464,14 @@ func NewCore(conf *CoreConfig) (*Core, error) {
 		enableMlock:                      !conf.DisableMlock,
 	}
 
+	if conf.ClusterCipherSuites != "" {
+		suites, err := tlsutil.ParseCiphers(conf.ClusterCipherSuites)
+		if err != nil {
+			return nil, errwrap.Wrapf("error parsing cluster cipher suites: {{err}}", err)
+		}
+		c.clusterCipherSuites = suites
+	}
+
 	c.corsConfig = &CORSConfig{core: c}
 	// Load CORS config and provide a value for the core field.
 

vault/request_forwarding.go

@@ -22,6 +22,7 @@ import (
 const (
 	clusterListenerAcceptDeadline = 500 * time.Millisecond
 	heartbeatInterval             = 30 * time.Second
+	requestForwardingALPN         = "req_fw_sb-act_v1"
 )
 
 // Starts the listeners and servers necessary to handle forwarded requests
@@ -45,7 +46,7 @@ func (c *Core) startForwarding() error {
 	}
 
 	// The server supports all of the possible protos
-	tlsConfig.NextProtos = []string{"h2", "req_fw_sb-act_v1"}
+	tlsConfig.NextProtos = []string{"h2", requestForwardingALPN}
 
 	// Create our RPC server and register the request handler server
 	c.clusterParamsLock.Lock()
@@ -144,13 +145,13 @@ func (c *Core) startForwarding() error {
 				}
 
 				switch tlsConn.ConnectionState().NegotiatedProtocol {
-				case "req_fw_sb-act_v1":
+				case requestForwardingALPN:
 					if !ha {
 						conn.Close()
 						continue
 					}
 
-					c.logger.Trace("core: got req_fw_sb-act_v1 connection")
+					c.logger.Trace("core: got request forwarding connection")
 					go fws.ServeConn(conn, &http2.ServeConnOpts{
 						Handler: c.rpcServer,
 					})
@@ -227,7 +228,7 @@ func (c *Core) refreshRequestForwardingConnection(clusterAddr string) error {
 	// the TLS state.
 	ctx, cancelFunc := context.WithCancel(context.Background())
 	c.rpcClientConn, err = grpc.DialContext(ctx, clusterURL.Host,
-		grpc.WithDialer(c.getGRPCDialer("req_fw_sb-act_v1", "", nil)),
+		grpc.WithDialer(c.getGRPCDialer(requestForwardingALPN, "", nil)),
 		grpc.WithInsecure(), // it's not, we handle it in the dialer
 		grpc.WithKeepaliveParams(keepalive.ClientParameters{
 			Time: 2 * heartbeatInterval,

vault/testing.go

@@ -1105,6 +1105,8 @@ func NewTestCluster(t testing.T, base *CoreConfig, opts *TestClusterOptions) *Te
 			coreConfig.Logger = base.Logger
 		}
 
+		coreConfig.ClusterCipherSuites = base.ClusterCipherSuites
+
 		coreConfig.DisableCache = base.DisableCache
 
 		coreConfig.DevToken = base.DevToken